This invention pertains to condensing mists and vapors onto the surface of a thin layer liquid film. It pertains particularly to a process for condensing hot flowing organic vapors onto a thin film of a hydrophilic liquid system supported on an exposed surface of a porous structure, and more particularly for condensing cooking oil vapors onto a thin film of water, and includes apparatus for achieving the vapor condensing process.
Condensing vapors onto the outer surface of heat exchanger surfaces or tubes is well known, such as used for condensing water vapor or steam from a turbine exhaust onto tubular surfaces of water-cooled heat exchangers to produce condensate for reheating and reuse. For such applications, the steam vapor is at a low subatmospheric pressure and the cooling water flowing through the impermeable tubes is at superatmospheric pressure such as 15-30 psig. Also, in some distillation processes a rising vapor is condensed against a cooler fluid within tubes of a heat exchanger. However, these known processes for condensing heated rising mists or vapors are not entirely satisfactory because the surfaces and the condenser are likely to become contaminated by the vapor, consequently the heat exchange will be altered. Moreover, direct contact of a mist or vapor with a liquid which is either miscible or immiscible provides better and more effective heat exchange than indirect heat exchange.